Understanding the social and behavioral context that leads to adolescents engaging in high-risk sexual behavior could make an important contribution to the prevention of an AIDS epidemic among young people. The proposed research will examine that context. High-risk sexual behavior is hypothesized to be more likely among adolescents who are engaging in other forms of problem behavior, and this constellation of sexual and other problematic behaviors is hypothesized to occur in a social context in which family members are coercive, uninvolved, unsupportive, and unavailable, and in which peers are engaging in deviant behavior. Adolescents whose social and behavioral context are problematic in this way are hypothesized to be more likely to lack (a) decision-making behavior that would prompt avoidance of unsafe sex and (b) social skills that would enable the person to cope with social influences to engage in high-risk sexual behavior. The proposed research to evaluate these hypotheses will be conducted in three components. Component A will develop instruments for assessing adolescents' decisional and social skills relevant to condom use and other means of avoiding STDs and pregnancy. Component B will be a prospective study of the relationship of social skills, decision-making, other problem behavior, family context, peer context and demographic factors to condom use and high-risk sexual behavior. Random-digit-dialing methods will be used to identify a representative sample of 600 sexually active adolescents; both the adolescents and their mothers will be assessed. In Component C, the situational and social competence factors associated with consistency of condom use will be intensively examined. A sample of 100 sexually active adolescents who are engaging in high rates of unsafe sexual behavior will complete a questionnaire every two weeks over a six-month period in order to pinpoint social and situational factors which are most associated with failure to use condoms. The research is expected to lead to the development of effective interventions to increase condom use-and decrease unsafe sexual behavior.